1. Field of the Invention
The present invention relates to a hydraulic braking pressure control unit.
2. Discussion of Related Art
There is known a hydraulic braking pressure control unit which includes a plurality of electromagnetically operated hydraulic pressure control valves capable of controlling brake cylinders, and hydraulic pressure detecting devices. The hydraulic pressure control valves and the hydraulic pressure detecting devices are held by a holder structure.
U.S. Pat. No. 5,577,813 (corresponding to JP-A-8-502007) discloses an example of such a hydraulic braking pressure control unit, which includes: (i) a power-operated hydraulic pressure source having (a) a pump device including a pump arranged to pressurize a working fluid received from a low-pressure source and deliver the pressurized working fluid, and a motor operable to drive the pump, and (b) an accumulator arranged to store the working fluid delivered from the pump device, (ii) a control valve device including at least one control valve each capable of controlling a hydraulic braking pressure in a brake cylinder for operating a brake, by utilizing the fluid delivered from the power-operated hydraulic pressure source, and (iii) a holder structure which has a first surface and a second surface opposite to each other, and a third surface adjacent to the first and second surfaces. The holder structure include first, second and third portions respectively having the first, second and third surfaces. The holder structure holds the power-operated hydraulic pressure source and the control valve device such that each of the above-indicated at least one control valve is attached at its main body portion to the first portion, and the motor is attached at its main body portion to the second portion, while the accumulator is attached at its main body portion to the third portion.